I have been reading the post about getting more boost and the VR4 upgrade. I have a 65' FB with a 349 stroker,ported heads and im chaging the cam to the "right" cam and supposedly 7 psi kit from Paradise Wheels and want about 10-11 psi. Is this possible or is the blower not capable in "stock" form. The motor will turn about 6800 rpm, so what size pulleys are needed if its possible.
Not possible. The Sn2000 can not produce enough boost to reach over 8psi on a 310ci engine keeping the blower safe and on a 349ci you will never get to that point without a VR4 kit.
i figured you'd know. So then why is ASP selling me pullies saying that it will get a another few pounds????Originally Posted by speedytang
Why not sell it to you if you will buy it.
Just from your engine picture I don't think your equiped for over 6psi to be honest. That flex tube for a discharge tube is not and will not help you at all. Your intake hose has to sharp of a bend to allow a unit to even get enough air to feed the SN2000 if even pushed. At WOT and you close the throttle blades that discharge pipe should have holes in it or expand like panty hose. With that stock blower pulley and if you have a 6.5" crank your past the safe margin by 5600 engine rpm. You put a smaller pulley(3.75") on that blower you will be at the max blower rpm by 5200 rpm so if that motor is built you won't even be in the power band of a 349ci before the blower runs out of power or destroys itself.
Both tubes have been changed to 3", the intake now had a smooth 90* also. My new cam will be more tame with a rpm range of 2000-6500 as oppsed to 3-8500 on the last one. So I should just leave it alone????
What is the VR4 upgraded?what does it cost and what will it do????
VR4 upgrade moves you to 14psi possible and from 780cfm to 1500 cfm. You can feed a engine of 454ci with a VR4 kit. Your piping looks much better by the way. lol
Now finding a VR4 upgrade is something else since they sold out back in June and the cost of manufacturing is so high not sure if we will ever see those kits new again. You will need to post your looking for one and expect to pay around $600 for the parts. If you plan to try a smaller pulley don't go under 4" unless you change to 8 rib or the belt will slip before you reach 5k rpm.
thanks for the info, thats about all i needed to know:happy:
You're going to have to do something about that intake hose. It looks crushed with the SN size snail on there, it's going to get pinchier with a VR4 mod.
Nice clean work in the engine bay there. Very good.
F=MA
I get 8.5 psi with my Sn2000 with the modified impeller. I have a camaro with a 355ci engine. VR4 will get you more cfm and boost. What boost levels are you currenlty runing? And do you have the modified impeller, curved blades?
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